Molding is a process by virtue of which a molded article can be formed from molding material by using a molding system. Various molded articles can be formed by using the molding process, such as an injection molding process. One example of a molded article that can be formed, for example, from polyethelene terephalate (PET) material is a preform that is capable of being subsequently blown into a beverage container, such as, a bottle and the like.
As an illustration, injection molding of PET material involves heating the PET material (ex. PET pellets, PEN powder, PLA, etc.) to a homogeneous molten state and injecting, under pressure, the so-melted PET material into a molding cavity defined, at least in part, by a female cavity piece and a male core piece mounted respectively on a cavity plate and a core plate of the mold. The cavity plate and the core plate are urged together and are held together by clamp force, the clamp force being sufficient enough to keep the cavity and the core pieces together against the pressure of the injected PET material. The molding cavity has a shape that substantially corresponds to a final cold-state shape of the molded article to be molded. The so-injected PET material is then cooled to a temperature sufficient to enable ejection of the so-formed molded article from the mold. When cooled, the molded article shrinks inside of the molding cavity and, as such, when the cavity and core plates are urged apart, the molded article tends to remain associated with the core piece. Accordingly, by urging the core plate away from the cavity plate, the molded article can be demolded, i.e. ejected off of the core piece. Ejection structures are known to assist in removing the molded articles from the core halves. Examples of the ejection structures include stripper plates, ejector pins, etc.
One consideration for economical operation of the molding system is cycle time or, in other words, time that elapses between a point in time when the cavity and core halves are closed and the molded articles are formed and a subsequent point in time when they are opened and the molded articles are removed. As one will appreciate, the shorter the cycle time, the higher the number of molded articles that can be produced in a particular mold in a given time. One attempt to minimize the cycle time is a so-called “post-mold cooling” process. Generally speaking, the post-mold cooling process involves removing the molded articles from the mold once they are sufficiently cooled to enable ejection of the molded articles without causing significant deformation to the molded articles during its transfer to an auxiliary cooling structure. Post mold cooling then occurs independently (but in parallel) to the injection cycle of the molding machine.
An example of the auxiliary cooling structure is disclosed in a commonly owned U.S. Pat. No. 7,104,780 issued to Domodossola et al. on Sep. 12, 2006. More specifically, Domodossola et al. discloses a platen-mounted, post-mold cooling apparatus for handling molded parts in an injection molding machine having a fixed platen, a movable platen, a core half, and a cavity half. A take-off device coupled to the fixed platen is configured to remove molded parts from either the core half or the cavity half. A treatment device coupled to the movable platen is configured to cool the molded parts carried by the take-off device. The take-off device extracts the just molded parts from the mold's core half and then moves linearly outboard of the mold halves. The subsequent movement of the movable platen to close the mold in the next molding cycle causes the treatment device's pins to engage the molded parts in the take-off device part carriers. When the movable platen opens again, the molded parts are extracted from the part carriers by the treatment device pins. When the movable platen is fully open, the treatment device is rotated to eject the cooled parts from the machine.
As will be appreciated by those of skill in the art, a pitch or a distance between the take-off device and the treatment device corresponds to a size of a molded article (such as a preform, for example) being produced. Due to various business considerations, an entity operating the molding system may choose to re-configure the molding system, for example, to change the shape and/or size of the preform to be produced. For example, the entity operating the molding system may choose to change molding cavities (for example, by exchanging mold cavity inserts, etc.) to produce preforms having a larger length or a smaller length. Should this occur, the entity operating the molding system will need to adjust the distance between the take-off device and the treatment device to accommodate the increased (or decreased) length of the molded articles (i.e. the preforms). A traditional solution to adjusting distance between the take-off plate and the treatment device is the use of either (i) a bolster plate or (ii) an adapter plate. The bolster plate has been traditionally attached between the movable platen and the treatment device; and has been used to increase the distance between the take-off plate and the treatment device, while the adapter plate comprises a bracket device which has been traditionally attached to the take-off plate to decrease the distance between the take-off plate and the treatment device.
One of the problems associated with this prior art approach is the time required to change the distance between the take-off plate and the treatment device by having to assemble and/or disassemble the bolster plate and/or the adapter plate. Another disadvantage of this prior art solution is increased costs attributed to the material cost associated with producing the bolster plate and/or adapter plate.